The present invention relates generally to control circuits, and more particularly, to sound detection control circuits for toys and other amusement devices.
Audible sound detection circuits are generally known in the art. One such audible sound detection circuit is disclosed in U.S. Pat. Nos. 5,493,618 and 5,615,271, both of Stevens et al. (hereinafter, “Stevens”). Stevens discloses a control circuit having a sound detector which is applied through a filter and a peak detector to a microcontroller and which is separately applied through an amplifier and a peak detector to the microcontroller. The microcontroller monitors both the filtered and the unfiltered inputs from the sound detector and counts the number of sounds (claps) detected within a window of time. The microcontroller must detect at least two sounds (claps) within a certain window or period of time, for example within 1.5 seconds. Alternate embodiments allow the microcontroller to take other actions when three sounds (claps) or four sounds (claps) are detected within the window of time. The Stevens circuit requires not only that the sounds be above a predetermined level, but also that two or more sounds above that level occur in sequence within the window of time.
Other, more complex prior art control circuits, such as those disclosed in U.S. Pat. Nos. 4,513,189, 4,641,292, 4,856,072 and 5,199,080, are responsive to voice activation. Generally, voice activated circuits require a complex voice recognition portion of the circuit including pattern analyzers, multiplexers, and memory for retaining a database of “learned” words. Most of the voice recognition circuits require the user to “train” the voice activated circuit to teach the circuit (database) words spoken by the user. Due to the complexity of the circuits, they tend to be expensive and not applicable to toys and games and the like. Furthermore, due to the complexity of training the circuits, they are not well suited to young children and/or children who cannot speak or cannot follow the instructions needed to “teach” the circuit(s).
There are many prior art toys that are responsive to remote controls that emit radio frequencies (RF) or infrared (IR) signals. The remote control responsive circuits require complex receiver circuitry and an antenna or photocell in addition to the control circuit. Furthermore, such circuits normally require a particular and separate remote control unit having a powered transmitter, antenna or infrared light emitting diode capable of emitting a complex communication signal outside of the audible frequency range. Normally such remote controls are complex in nature having buttons, knobs, dials, joysticks and the like, and require a certain degree of dexterity by the user. Furthermore, the additional remote control circuit adds unnecessary expense to a toy or an amusement device which only needs an initiation or trigger signal.
What is needed but not provided by the prior art is an inexpensive and easy to use remote control system, especially one simple enough for literally an infant to use.